1. Field of the Invention
The present invention concerns a method for generating a three-dimensional ultrasound image that is, in particular used in the monitoring and visualization of the disintegration of a calculus in lithotripsy.
2. Description of the Prior Art
During the course of a lithotripsy procedure for disintegrating, for example, a kidney stone, it is desirable to achieve the disintegration as efficiently as possible. This means that the fewest possible shockwave pulses should be applied to the patient, and the pulses should be applied in a manner that minimizes the discomfort to the patient. To assist in both of these goals, it is desirable to be able to visualize the successive disintegration of the calculus and its environment, after the application of each shockwave pulse, in a three-dimensional presentation.
Such a three-dimensional visualization is possible with a device as is known, for example, from M. Bechtold, B. Granz, R. Oppelt, “2-D Array for Diagnostic Imaging”, IEEE Ultrasonics Symposium 1996, pages 1573-1576. The using a two-dimensional ultrasonic transducer arrangement of 64*64 transducer elements, a three-dimensional image is generated by phase-delayed control of transducer elements.
A three-dimensional ultrasound image also can be generated with a one-dimensional ultrasonic transducer arrangement, the transducer elements of which are controlled with phase-delays, and a B-image can be generated by electronic scanning (linear phased array). A series of two-dimensional images (B-image) is generated, with the images at respectively known scan positions, by a mechanical scanning perpendicular to the B-image plane. The series of these B-images is then combined into a three-dimensional image.
A method for generating a three-dimensional ultrasound image with a linear ultrasonic transducer array is known from German OS 98 28 947, in which the three-dimensional image is likewise composed of a number of B-images that arise in temporal succession given a movement of the linear ultrasonic transducer array. A dimensionally correct reproduction of a three-dimensional ultrasound image is also possible by means of a special evaluation of the temporally successive B-images when the movement ensues non-uniformly and, for example, is implemented manually by the operating personnel. Suitable commercial software for this purpose is available from Siemens AG under the trade name 3-Scape.